1. Field of the Invention
The present invention relates to a method of disinfecting a foodstuff using gaseous ozone whereby the quality of the foodstuff so treated can be maintained over time.
2. Description of the Background
Ozone has been used as a disinfectant/oxidant in the food industry for several decades and is commercially available. Ozone is generally produced by subjecting oxygen to ultraviolet radiation having a wavelength below 200 nm or by corona discharge, and has been used in bulk storage of produce and in disinfection of water either in municipal drinking facilities or for waste water treatment. Disinfection processes have been developed using ozone solutions by bubbling ozone gas through water to sanitize/disinfect food products. Although some gaseous ozone treatments have been proposed for the sterilization of foodstuffs, all lack effective means for delivering gaseous ozone or mixtures containing the same to or into the foodstuffs being treated.
The following U.S. patents are noted.
U.S. Pat. No. 5,431,939 describes a method for treating a shell egg using biocidally active gases including ozone, however, the process requires heating the egg to more than 129.9.degree. F. At elevated temperatures, ozone is more unstable and easily decomposes.
U.S. Pat. No. 4,549,477 describes an ozone treatment apparatus for treating food using a conveyor means for continuous processing. However, such a process design renders it impossible to employ vacuum and/or pressure during gaseous ozone treatment.
U.S. Pat. No. 5,227,184 describes a method for sanitizing food products using aqueous ozone.
U.S. Pat. No. 4,376,130 describes the ozonolysis of whole cardamon seeds using aqueous ozone.
U.S. Pat. No. 4,849,237 describes a method for sanitizing poultry carcasses using aqueous ozone.
U.S. Pat. No. 4,256,574 describes an ozone system for applying ozone to waste water for disinfection.
U.S. Pat. No. 5,053,140 describes an apparatus and a process for applying ozone to waste water to remove fats, solids and bacteria therein.
U.S. Pat. No. 5,087,466 describes a process for treating animal flesh to remove color and odor. The flesh is mixed with water and this aqueous mixture is placed in contact with ozone.
U.S. Pat. No. 5,015,442 describes an apparatus for sterilizing and deodorizing air to remove odors therefrom.
U.S. Pat. No. 5,011,599 describes a process for decomposing the herbicide, atrazine, in waste water.
U.S. Pat. No. 5,213,759 describes a method of sterilizing microorganisms by using both ozone gas and ultraviolet radiation to obtain a synergistic effect.
U.S. Pat. No. 5,011,699 describes a process for sterilizing foodstuffs using mixtures of ozone gas, carbon dioxide and nitrogen using high concentrations of ozone, i.e., from 33.3% to 66.7% of ozone.
U.S. Pat. No. 5,281,428 describes a method and apparatus for treating and packaging raw meat by first exposing the meat to a vacuum, flushing the surface of the meat with an air-free treatment gas, and re-exposing the meat to vacuum.
The shortcomings of such conventional methods for sterilizing foodstuffs, and particularly, with gaseous ozone is unfortunate as microbial growth in foods is a primary problem for public health. If pathogenic microorganisms are present in foods, food-borne outbreaks may occur that can cause significant economic loss. In 1997 alone, there were 9,000 estimated deaths and over 15 billion dollars of total cost associated with food-borne illnesses.
Food spoilage and/or pathogenic microorganisms primarily originate from ingredients in foodstuffs or from cross-contamination from contact with surfaces or environments during manufacturing processes. Currently, food manufacturers use different methodologies to eliminate, retard or prevent microbial outgrowth, such as heating and irradiation. Unfortunately, an effective means for inhibiting or preventing microorganism growth in foodstuffs remains elusive.